Several applications are known in which connections need to be provided underwater, such as electrical connections or optical connections. Examples include a subsea installation for the production of hydrocarbons from a subsea well, in which different components of the subsea installation may need to be connected for power transfer and/or data communication. Such connections may for example comprise a connection from a topside installation, such as a floating or fixed platform, or from an onshore site to a subsea component, e. g. by means of an umbilical or a subsea cable. Other connections include electrical connections between different type of subsea equipment, such as a connection between a subsea transformer and a subsea switchgear, a data connection between different control modules or between a hub and a satellite well. In some configurations, such connections need to transport significant amounts of electrical power. It is desirable to provide connectors that are capable of transporting electrical power at high voltages.
During the assembly or termination of subsea connectors, there might be operations where for example a shaft is inserted into a blind hole of a housing with barrel seals providing a sealing between the shaft and the housing. In such operation, a volume of air can be trapped between the connector parts when the barrel seal is engaged. When the volume is reduced during mating, the pressure of the trapped air increases. This is generally not a problem, and as a result, the force required to mate the two connector parts only increases slightly. In particular, such dry mating procedures of two connector parts are generally unproblematic in the currently used voltage ranges of subsea connectors. In known systems, it is accepted that an additional force will be required to compress the air during the mating process.
It is desirable to provide subsea connectors that are operable at higher voltages than the presently used connectors, for example at voltages in excess of 10,000 V.